A. J. Grove 
21 
the dorsal system thus formed by the anastomosis of these branches, 
are not connected with one another except in the seventh abdominal 
segment, where the posterior branches formed by the bifurcation of the 
seventh dorsal tracheae meet in the middle line, forming a connection 
between the two lateral systems. 
The first thoracic stigmata. From the first thoracic stigma on 
each side, in addition to the dorsal trachea which joins the long 
connective, a large branch is given off near the commencement of the 
main trachea. This extends in an oblique direction towards the 
median line of the head, and during its course gives off smaller 
branches to the surrounding parts. Having arrived at a position 
opposite to the base of the antenna, it turns abruptly, passes to the 
insertion of the antenna, and continues along it nearly to its extremity. 
The second thoracic stigmata. A lateral branch is given off near the 
beginning of the dorsal trachea arising from the second thoracic stigma, 
but this does not give off any supplementary branches. 
The abdominal stigmata. Near the commencement of the dorsal 
trachea which proceeds from the first abdominal stigma on each side, a 
small branch is given off which extends in an anterior direction. From 
this the ventral branch in this case originates; in all other cases it is 
given off from the main trachea proceeding from the stigma. From the 
sixth dorsal branch on each side, a small trachea is given off to the 
cornicle, to which it is adjacent. This is not shown in Text Fig. 13, 
because for some reason it had become invisible in the specimen from 
which that drawing was taken. 
The ventral tracheal system. In this system (Text Fig. 14) it is 
only the ventral branches given off from the abdominal stigmata which 
are connected up by the longitudinal trachea. Those from the thoracic 
stigmata are not so connected. The fusion is effected in exactly the 
same way as in the case of the dorsal system—the ventral branches, 
with the exception of the first, dividing when they have reached a 
position about half way towards the ventral median line, the branches 
so formed joining up to constitute the long connecting trachea, which, 
in this case, will only extend from the first to the seventh abdominal 
segment. 
As in the case of the dorsal system, small tracheae are given off 
from the long connectives into the central space. These dip down 
and aerate the tissues in their immediate vicinity. 
Another feature in which the ventral differs from the dorsal system is 
that each of the main ventral branches from the opposite thoracic stigmata 
